1. Field of the Invention
The present invention relates to image data compression. More specifically, the present invention relates to a technique of compressing image data and generating a new data structure that preferentially retains and enhances image data information important to human perception.
2. Description of Background Art
The storage and retrieval of digital image files is widespread. It finds applications in digital cameras, computer animations, etc. One challenge is file size and data transfer rates. As images have met and exceeded photo quality thresholds, the resultant image files have become large. This is most noticeable for someone with a slow connection to the internet who must download a long image based document such as a PDF document or an image file.
This is because the files are typically stored in pixel form, wherein each location or pixel on an image is stored as a five or more dimensional data point, including location (x, y, and perhaps z) and color (RGB). There are various compression techniques that deal with such images, but issues include reduction in image quality.
For example, two of the industry standard compression methods, JPEG and MPEG, have issues with level of compression and scaling. For example, when a photograph is compressed with JPEG, it tends to render a very good image below a certain zoom factor. When it is enlarged beyond a certain point, however, “stairstep” artifacts in the image begin to occur.
What is needed is a fast compression and rendering technique that preserves the visually important information for an image at varying zoom factors while providing a drastic decrease in required memory and processing requirements for storing, displaying, transmitting, zooming, and rotating an image.